...was in homage to a similar sequence from Nick Fury Agent of SHIELD #2 (1968):

Now, the interesting story is that Jim Steranko's Nick Fury work was frequently censored by Marvel because it was too sexy and suggestive. The tribute page from X-Men tries to repair the damage, as if to say "we assistant editors are in charge, there will be no censorship". So for example, Steranko had the cleavage he drew on Val erased, so the tribute gives her loads of it (oh my teenage oats!). Then there's the phone, which was redrawn by another artist to be ON rather than OFF the hook. I suppose the console drawn by Michael Golden there is off, but what the heck was Marvel thinking? And finally, there's the last panel of Nick and Val in an embrace - the tribute page will make it quite clear they're having sex - famously changed to something much MORE suggestive, a big gun in a holster. Oh myyyyyy. Steranko apparently thanked his editor for that one. For comparison's sake, here is the original Steranko layout: